Evaluation of the Elecsys Chagas Assay for Detection of Trypanosoma cruzi-Specific Antibodies in a Multicenter Study in Europe and Latin America

Abstract

Serology is the preferred method to confirm a Chagas disease diagnosis and to screen blood donors. A battery of assays is often required due to the limited accuracy of single assays. The Elecsys Chagas assay is a newly developed, double-antigen sandwich assay for use on the Elecsys and cobas e immunoassay analyzers, intended to identify individuals infected with Trypanosoma cruzi, for diagnosis and screening. The performance of the Elecsys Chagas assay was evaluated in comparison with those of other widely used T. cruzi antibody assays, at multiple sites (Europe/Latin America). Relative sensitivity and specificity were assessed by using samples from blood donors, pregnant women, and hospitalized patients from regions where Chagas disease is endemic and from regions of nonendemicity. The Elecsys Chagas assay had an overall relative sensitivity of 100% (n = 674). Overall relative specificities were 99.90% (n = 14,681), 100% (n = 313), and 100% (n = 517) for samples from blood donors, pregnant women, and hospitalized patients, respectively. The analytical specificity was 99.83% (n = 594). The Elecsys Chagas assay detected T. cruzi antibodies in two World Health Organization (WHO) standard T. cruzi reference panels (panels 09/188 and 09/186) at a 1:512 dilution, corresponding to a cutoff sensitivity of approximately 1 mIU/ml. The Elecsys Chagas assay demonstrated robust performance under routine conditions at multiple sites in Europe and Latin America. In contrast to other available Chagas assays, the Elecsys assay uses a reduced number of recombinant T. cruzi antigens, resulting in a significantly smaller number of cross-reactions and improved analytical specificity while being highly sensitive.

Cross-Reactivity Using Chimeric Trypanosoma cruzi Antigens: Diagnostic Performance in Settings Where Chagas Disease and American Cutaneous or Visceral Leishmaniasis Are Coendemic

“…cruzi antibodies when assayed by Elecsys Chagas, an automated electrochemiluminescence immunoassay employing soluble forms of recombinant T. cruzi antigens derived from flagellar calcium binding protein, flagellar repetitive antigen, and cruzipain (39).…”

Clinical and epidemiological aspects of chronic Chagas disease from Southern Brazil

“…Positive serology for anti- T. cruzi antibodies was based on Chemiluminescence Microparticle Immunoassay with 100% sensitivity (95% CI: 97.90 to 100%) and 99.93% specificity (95% CI: 99.80 to 99.99%) (Architect Plus Chagas, Abbott, USA) 19 , and indirect immunofluorescence with 100% sensitivity and specificity (IMUNO-Con Chagas, WAMA diagnóstica, Brazil) 20 assay 21 .…”

Mixed infections by different Trypanosoma cruzi discrete typing units among Chagas disease patients in an endemic community in Panama

“…Chagas disease or American trypanosomiasis is a zoonosis spread from the southern USA to approximately the Río Negro in Argentina, whose causative agent is the hemoparasite Trypanosoma cruzi [1]. This infection is transmitted to humans through different routes: i) by direct contamination of the mucosa with the feces of the vector triatomine insects; ii) by ingesting food contaminated with the feces of the vectors; iii) by congenital vertical transmission, and iv) by blood transfusions or transplants of infected organs [1][2][3][4]. Currently, the estimated number of patients infected with T. cruzi is 6-8 million and 120 million people are at risk of infection.…”

“…Approximately two months after the onset of infection, the chronic phase starts in 70% of the patients and there may be no symptoms even after many years of evolution [ 11 , 12 ]. The remaining 30% of chronic patients develop heart disease of different degrees, representing the majority of deaths due to Chagas disease [ 4 , 13 ]. In addition, 10% of these patients may also develop digestive alterations such as megacolon and megaesophagus as well as neurological alterations or a combination of both [ 4 , 14 , 15 ].…”

“…The remaining 30% of chronic patients develop heart disease of different degrees, representing the majority of deaths due to Chagas disease [ 4 , 13 ]. In addition, 10% of these patients may also develop digestive alterations such as megacolon and megaesophagus as well as neurological alterations or a combination of both [ 4 , 14 , 15 ].…”